The main risk of pushing yourself hard in the first few weeks is that your heart and lungs improve quicker thatn the mucles/ joints/ bones in your legs, - it is easy to give yourself a leg injury by over- doing it, and at 6 weeks in, you're crocked. By all means keep going with the C25k, but don't strive for a PB every time you go out- slow and steady wins the race!
Why not do a park run every month or so, rather than every week? - otherwise you'll just have a nother few days of being knackered after the event, and you'll not be able to keep doing that regularly without damaging your self.
You can always offer to volunteer at the parkruns too- beingpart of the park run "family" will keep you enthused, as well as doing the runs.
Elspeth- will I see you at Glen Ogle?- I'm aiming for a pleasant bimble around at the back of the field= I have'nt run more than 5 miles since the CS 40, and have a recovering calf tear, and a stiff knee( produced by the funny gait I adopted to compensate for the calf, I think).
Hoping to manage a short run at Strathy park tomorrow- my OH is going there anyway for a meeting, so may as well give it a try, but I am abit unsure about hills! ( Not an especially good position to be in when the next race is a hilly one!)